Professor David Wilson, the UK's leading criminologist, presents the third series of Crime Files, this time focusing on cold cases. In Episode 6, David travels to Coatbridge, South Lanarkshire to explore the case of Moira Anderson who vanished during a blizzard in 1957. He'll learn about a dark family secret and discuss the concept of living with a guilty conscience.David meets Sandra Brown, a child protection campaigner and author who has a personal link to Moira Anderson's disappearance. Sandra recalls her memories of Coatbridge from the 1950s and tells David about the family secrets which have affected the trajectory of her entire life.Consultant forensic psychologist Vicky Thakordas-Desai talks to David about the psychology of guilty. They discuss how guilt might manifest itself in people and what factors might lead a person to confess to their crimes.David's final guest is Dr Dan Rusu who has researched murderers, and how they integrate into society after serving life sentences for their crimes. David speaks with him about how these criminals handle their past and if it is possible for them to be forgiven by the community.